The Concordian who researches your fight-or-flight response

Ghazal Mohammadi measures how people's immune systems react when their hands are placed in cold water.

October 9, 2018

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By Kenneth Gibson

Photo by Norhan Mehrez

Submerging your hand in a cold bath may bring a shiver to your spine, but Ghazal Mohammadi is more interested in your immune system’s reaction.

Mohammadi’s research is focused on immunoglobulin-A (Ig-A), the most abundant antibody inside the body’s mucus membranes. Ig-A is the first line of defense for the body’s immune system and guards sites, such as the mouth, from pathogenic invasions.

Using a cold pressor test that is set for 3 degrees Celsius, Mohammadi submerges a person’s hand, up to about the wrist area, in a cold bath for two to five minutes. The water — whose temperature is between 2 and 5 degrees Celsius — engages the sympathetic nervous system, which controls the body’s fight-or-flight response. Ig-A response can be detected in different cells after a stress stimulus such as this.

Ghazal Mohammadi: This is a microplate — or Biotek plate reader — which has the capacity to read enzyme-linked immunosorbent assay (ELISA) kits. These kits are used to measure cell concentrations or detect molecules. This device is capable of quantifying the light wavelength transmitted through the liquid inside the ELISA plates, which contain the Ig-A antibody or other cells. In our study, we applied cold exposure and took saliva samples before and after the test. The samples were then analyzed with an Ig-A ELISA kit using the microplate reader. From there, we analyzed the Ig-A concentration before and after the cold pressure test to study the connection between the sympathetic nervous system and the immune system.

What is the hoped-for result of your project? And what impact could you see it having on people's lives?

GM: We might have found clues that demonstrate that Ig-A changes when faced with stressors. Our data shows that Ig-A’s reaction to cold exposure is based on individual baseline measures, which supports Wilder’s law of initial values. The theory is that the way people react to stimuli depends on their baseline values because the body tries to balance its state and reach homeostasis. The response pattern indicates that after exposure to a stressor, those with high baselines might have a decrease in their values, while those with low baseline measures might have an increasing rate of targeted values. Individuals whose baseline measures were at the mid-point might not experience any significant change in Ig-A antibody concentration.

These results will help analyze and interpret results for studies that use Ig-A as a dependent variable. The findings will also further our understanding of the interindividual variations in Ig-A responses to a physical cold stressor.

What are some of the major challenges you face in your research? What are some of the key areas where your work could be applied?

GM: Getting conclusive results in stress-immunology studies is challenging because immune system behaviour is based on the genes people have had since birth. Moreover, as a human body grows and faces different obstacles, the immune system starts to adapt. Because people’s genes and environments vary so widely, irrefutable evidence is hard to come by.

Working with saliva samples is also challenging since the duplicates and solution pipetting must be precise. Also, we need to be cautious with any study involving humans as test subjects and recruiting participants requires patience.

Ig-A concentrations are directly affected by upper respiratory tract infections, mostly among athletes. Our research could be interesting to immunologists studying Ig-A, doctors who treat patients with upper respiratory tract infections and athletes who are at risk of being infected due to their intense exercise routines.

What person, experience or moment in time first inspired you to study this subject and get involved in the field?

GM: My father was a nurse and always recounted stories about science breakthroughs with enthusiasm in his eyes. My mother inspired me to continue my scientific career even in hard times. All in all, my family taught me how to push forward.

The focus of my current research originated from my first experiment. I was investigating the effects of group based aquatic exercise and Swedish massage on the immune systems of people affected by multiple sclerosis. This experience showed me how important the immune system is to preserving our health and how it can be affected by stressors in our daily lives.

How can interested STEM students get involved in this line of research? What advice would you give them?

GM: The human body is made up of billions of cells, and stressors makes it a challenge for each cell to survive. We are no different than what is going on inside our bodies. Anyone who is interested in a STEM field is going to face challenges, be pushed to their limits and encounter failure. What defines success is your reaction to these stressors and how you deal with problems.

What do you like best about being Concordia?

GM: Concordia cares about me, my research, my health, my mental state and my living conditions. At the university, I have a peaceful library to study in and a health centre where I can heal. Concordia also has many staff members that have helped me in numerous ways, from IT services to writing tutors to immigration advisors. The quality of services the university offers is notable.

Are there any partners, agencies or other funding/support attached to your research?